python - Django 通用外键 : accessor clash when 2 models have same related_name

Question

当我 syncdb 时，我收到许多这样的错误:

   transcription.transcription1: Accessor for field 'participant_content_type' clashes with related field 'ContentType.auxi
    liary_model_as_participant'. Add a related_name argument to the definition for 'participant_content_type'.
    transcription.transcription1: Reverse query name for field 'participant_content_type' clashes with related field 'Conten
    tType.auxiliary_model_as_participant'. Add a related_name argument to the definition for 'participant_content_type'.

我的模型已有相关名称:

# my base class which I intend to inherit from in many places.
# Many types of AuxiliaryModel will point at participant/match objects.:
class AuxiliaryModel(models.Model):
    participant_content_type = models.ForeignKey(ContentType,
                                                 editable=False,
                                                 related_name = 'auxiliary_model_as_participant')
    participant_object_id = models.PositiveIntegerField(editable=False)
    participant = generic.GenericForeignKey('participant_content_type',
                                            'participant_object_id',
                                            )

    match_content_type = models.ForeignKey(ContentType,
                                           editable=False,
                                           related_name = 'auxiliary_model_as_match')
    match_object_id = models.PositiveIntegerField(editable=False)
    match = generic.GenericForeignKey('match_content_type',
                                      'match_object_id',
                                      )

    class Meta:
        abstract = True


class Transcription(AuxiliaryModel):

    transcription = models.TextField(max_length=TRANSCRIPTION_MAX_LENGTH,
                                        null=True)

    class Meta:
        abstract = True

class Transcription1(Transcription):
    pass

class Transcription2(Transcription):
    pass

class Transcription3(Transcription):
    pass

当我注释掉 Transcription2 和 Transcription3 时，问题就消失了，所以看起来是 related_names 冲突。我必须让它们独一无二吗？如果是这样，有没有一种方法可以做到这一点，而不必在每个子类中编写样板代码？

Answer 1

来自 Django 文档 https://docs.djangoproject.com/en/dev/topics/db/models/#be-careful-with-related-name :

If you are using the related_name attribute on a ForeignKey or ManyToManyField, you must always specify a unique reverse name for the field. This would normally cause a problem in abstract base classes, since the fields on this class are included into each of the child classes, with exactly the same values for the attributes (including related_name) each time.

To work around this problem, when you are using related_name in an abstract base class (only), part of the name should contain '%(app_label)s' and '%(class)s'.

在这种情况下，我认为这会起作用:

    participant_content_type = models.ForeignKey(ContentType,
                                             editable=False,
                                             related_name = '%(app_label)s_%(class)s_as_participant')
    match_content_type = models.ForeignKey(ContentType,
                                       editable=False,
                                       related_name = '%(app_label)s_%(class)s_model_as_match')

因此，使用 %(app_label)_transcription2_as_participant 您可以访问 Transcription2.participant_content_type 的反向内容